Yep. Wherever I see it, ridicule is typically counterproductive. If people don’t engage fairly (as you point out), after being warned people lose the opportunity to post. That, it seems to me, is the job of the moderator. But to go down to that level? No, not a good idea.
This is one of the cultural problems we are facing today, that people start with disrespect. We don’t have to respond in kind.